Roots: Minority Report. The story's title quotes Roosevelt: "Men are not prisoners of fate but only prisoners of their own minds." The Book of Acts "You gave everyone on the planet the gift of tongues" says the Doctor to his original TARDIS. Tegan mentions the paintings of Brueghel. Adric's disguise is based on that of Galen of Pergamum (see: Unrecorded Adventures) Tegan refers to Turlough "going walkabout".
Goofs: 'I don't have a son, I'm only 20 years old', says Nyssa. Which says something about the biology of Trakenites - or something about her knowledge of biology [or perhaps it's just a terrible lie?]
On the Day of the Miracle: everyone on Valderon woke up to discover they could speak every language in the known universe as if it was their own, due to the influence of the Type 50. This contradicts The Christmas Invasion's assertion that a TARDIS' pilot must also be present [perhaps this is a feature of the Doctor's Type 40 that was improved upon in later models, including the Type 50?]
Dialogue Triumphs: 'This gadget of yours might be handy for a weather forecast but you can't use it as a basis for a judicial system!'
Dialogue Disasters: 'I've become a different person, Doctor - cold, lonely and bitter'
Continuity: Adric (full name Adric Serenous Traken) is the younger child of Nyssa. When he was a little boy, Nyssa used to tell Adric stories of her time with the Doctor (see: Links). Adric's family learn of Nyssa's disappearance on Helheim on 'Quintillus' 1st 3531
Valderon is a penal colony, reliant on its array of microwave antennae to capture the electromagnetic energy it needs to sustain its population, many of whom are now being used as guinea pigs for research into Richters Syndrome. The planet is 'Earth-type' with Earth normal air and gravity.
Nyssa left for Helheim in 3530, fifty years after terminus
The Doctor says he left Gallifrey in a hurry "about six hundred years" ago, but left with the 'wrong' TARDIS - his Type 40, rather than his first, a Type 50 symbiotically linked to him through an 'imprimatur' When it left Gallifrey the Doctor's Type 50 TARDIS broke free of its dimensional stabilisers, burned out its recall circuits (link), jettisoned three quarters of its internal architectural configuration and ripped through the transduction barriers, which are described here as a quantum force field.
The Type 50 can see into the future but presumably not the Doctor's ability to change its plans (shades of the Cassandra complex?). It spent twenty years on the planet, with only its psychic circuitry still intact, reaching out to the vulnerable TARDIS companions Tegan (weakened by the Mara) and Turlough (weakened by Eldrad) A departing TARDIS leaves a residual temporal trace lasting up to thirty minutes.
Nyssa learns that Lysarti died "alone and heartbroken" during her absence.
The Doctor's Type 50 TARDIS shows him his next three incarnations, calling them "The rhetorician, the Schemer, and the Idealist."
Links: This story concludes Nyssa's 'Richter's Syndrome' arc initiated in Cobwebs and heavily references the events of Circular Time: Winter. Mention is made of the influence of the Mara on Tegan (Kinda, Snakedance, Cradle of the Snake) and Eldrad on Turlough (Eldrad Must Die!) Tegan refers to "two Brigs" and being 'Blinovitched' (Mawdryn Undead) Adric mentions the Doctor and his companions visiting Earth in the Seventeenth Century (The Visitation), Omega (Arc of Infinity) and the Cybermen and [his namesake] Adric (Earthshock). Turlough mentions Purity (The Whispering Forest), Vectris (Kiss of Death), Sontarans (Heroes of Sontar), and Homogenite (The Emerald Tiger). Among the time sensitive races the Doctor mentions being able to see into the future are Tharils (Warrior's Gate), Jagaroth (City of Death), Xeraphin (Time Flight) and the Time Lords. Nyssa refers to the Melkur (Keeper of Traken). Audio clips from other (mainly Morris-scripted) stories include: Bloodtide, The Crimes of Thomas Brewster, Flip-Flop, Protect and Survive, The Cannibalists, The Resurrection of Mars and Army of Death. The Type 50 activates the Type 40 TARDIS's state of temporal grace.
Unrecorded Adventures: The Doctor claims that he met Galen of Pergamum (You are remarkably informed" "-That's what he said!")
Q.v.: 'Tracking through Time', 'The TARDIS State of Temporal Grace'.
Future History: Humanity is spread across seven galaxies by 3556.
Location: The penal colony of Valderon, 3556.
The Bottom Line: 'You're nothing more than a castle built on broken dreams.'
Headache-inducing paradoxes fuel both the TARDIS antagonist of this story, as well as the story itself, harking back to Circular Time. It's definitely not a story for the new listener, and its rough treatment of paradoxes (would the Doctor feigning ignorance in the future really prevent a paradox? It scarcely seems credible) may well undermine the story for some. The sound design is lovely, however, Davison-era-inspired music and squeaky sandshoes included.
Nyssa's second life after Terminus begins around the year 3530, the nominated date of that adventure. After leaving the medical station she meets Lasarti and survives something referred to as 'the Corporation Wars' (it is not clear which of these occurs first.) They settle down on Zarat and have two children, a girl, Neeka, who is apparently very like Tegan, and Adric. Just after Adric has been born and while Neeka is still an infant, Nyssa is reunited with the Doctor at the end of his fifth life, helping him through his regeneration (Circular Time: Winter). Twenty years after her time on Terminus, and with Adric now in his teens, Nyssa leaves for Helheim and is declared missing a year later; this affects her family deeply and they become itinerant; Lasarti buries himself in his work, and the now-adult Neeka and Adric find their calling in life as aid worker and xeno-medic respectively - presumably inspired by their mother's life and her stories. Lasarti dies, heartbroken, in 3546.
When Nyssa is reunited with the Doctor in Cobwebs she is aware that in his future he learns of Neeka and Adric for the first time (Circular Time: Winter), and makes all attempts to hide their existence from him so as to protect his future regeneration from a damaging paradox. It is this paradox which gives power to his Type 50 TARDIS in Prisoners of Fate.